Circuit controlling device



' May 28, 1935.

C. F. WALLACE CIIRCUIT CONTROLLING DEVICE Original Filed Aug. 29,l92'7// 3 Sheets-Sheebl I; A TTORNEY May 28, 1935. c. F. WALLACE CIRCUITCONTROLLING DEVICE Original Filed Aug. 29, 1927 3 Sheets-Sheet 2 1.3,QTTOR-NEY y 8, 1935. c. F. WALLACE 2,002,804

CIRCUIT CONTROLLING DEVICE- Original Filed Aug. 29, 1927 5 Sheets-Sheet3 QHYVENTUR I; A TTORNE Y Patented May 28, 1935 UNITED STATES PATENTOFFICE CIRCUIT CONTROLLING DEVICE Original application August 29, 1927,Serial No.

216,080. Divided and this application August 11, 1933, Serial No.684,631

4 Claims.

This invention relates to circuit controlling devices, and moreparticularly to devices for intermittently closing and opening anelectric circuit, such, for example, as the feed circuit of a lamp usedin a signal device of flash-beacon type.

It is an object of the present invention to provide simple but reliablyoperative means for causing periodic circuit closure with a minimum ofsurface friction and with a minimum net loss of energy in the actuatingmeans.

As many flash-beacon signals are located in remote places where they aredependent on battery operation, and frequently on dry batteries, it isimportant that the apparatus be constructed to operate with a lowconsumption of current. In the flash-beacon of my application Serial No.216,080, filed August 29, 1927, of which this is a division, theduration of each flash is very short, and as the actuating devices orcircuit controls operate with small demand on the source of electricalenergy, the apparatus may stand in operation for long periods of timewithout attention. The present invention is, therefore, particularlysuited to meet the requirements of flash-beacon signals, although,obviously, it may serve other purposes.

To demonstrate the relation of the general principle of the invention toa specific condition, the invention is shown in the drawings and ishereinafter described in connection with the electromagnetic pendulumcontrol of the flashing-light signal system of my said applicationSerial No. 216,080.

In the drawings:

Fig. 1 is a back elevation of a signal device embodying the invention,with the back cover broken away;

Fig. 2 is a side elevation with the casing sectioned on the line 2-2 ofFig. 1 and its rear portion cut away;

Figs. 3, 4 and 5 are enlarged detail views showing the positions of thependulum and trip bar shown in Fig. 1 at various different times duringthe operation of the device;

Fig. 6 is a side elevation of the light carrier which is shown from theother side in Fig. 2;

Fig. 7 is a plan View of the light carrier partly sectioned on the line1| of Fig. 6;

Figs. 8 and 9 are enlarged fragmentary back elevations showing differentpositions of the switch operating mechanism shown in Fig. 1;

Fig. 10 is a diagram of the electric connections of the device; and

Fig. 11 (on Sheet 1) is an enlarged fragmentary vertical section takenon the line l|-ll of Fig. 6 showing the lamp contact mechanism.

The signal device illustrated in Figs. 1 to 11 has a casing It] providedwith a removable back cover H. In the upper part of the front wall ofthe casing is a window l2 behind which is a parabolic reflector [3having a vertical slot 14 in its central portion. The working parts ofthe device are supported from a main bracket 15 which is rigidly held inthe central portion of the casing by bars I6 secured to posts I!projecting inwardly from the front wall of the casing.

The signal device is provided with a movable 'lamp carrier 20, which canbe made to carry any desired number of incandescent electric lamps Zia,Zlb, etc. A pair of electric terminals 22, 23am so arranged that themovement of the carrier 20 causes the electric lamps to be successivelyconnected in a lighting circuit. The carrier 20 is in the form of awheel having a shaft 24 journaled in two posts 25 rising from the top ofthe main bracket [5. The shaft 24 and the inner portion 26 of the wheelare of conducting material, while one side and the periphery of thewheel are made of insulating material 21. Lamp sockets 28 are securedabout the periphery of the portion 21, and the inner terminal 29 of eachsocket is insulated from the side wall of the socket and is connected bya screw with the conducting portion 26 of the wheel and is thus groundedthrough the shaft to the bracket, so that in this instance the terminal23 is the grounded metallic portion of the wheel 20. To the peripheralportion of each socket is connected a wire 30 which extends radiallyinward along the insulated face of the wheel. The wire 30 of each lampcomes in contact with the spring terminal 22 when the lamp is positionedat the focus of the reflector 13. Thus, when the lamp carrier 20 isrotated, the lamps are successively brought into the focus of thereflector and into circuit between the terminals 22 and 23.

The device has an oscillating member, which most desirably and as shownis a magnetic pendulum 40 formed by a U-shaped bar 4| magnetized in itslower central portion as indicated on Fig. 1 and supported by atransverse bar 42, which has secured at its center a thin upwardlyprojecting plate 43 by which the pendulum is suspended from staples 44projecting downwardly from a plate 45 secured to the top of the mainbracket 15, the staples passing through openings in the plate 43. Thebearing provided by the staples 44 in the plate 43 is located above thecenter of gravity of the pendulum but considerably below its upper end,the pendulum being a compound pendulum and being proportioned accordingto the period of oscillation desired.

A fixed coil bil surrounds the lower magnetized part of the bar l! ofthe pendulum, and the ends El, 52 of this coil are connectedrespectively with the terminals'22 and 23 (see Fig. 10) The end 5i ofthe coil is secured to a binding post 53 mounted on an insulating bar 54carried by the main bracket, and this post is connected by a conductor55 to the terminal'ZZ. The end 52 of the coil is grounded to the mainbracket, and is thus connected to the grounded lamp terminal 23.Consequently, when the filament of theelectric lamp 2m is intact, thecoil 55 is in a closed circuit. Under these circumstances, the oscillaetion of the pendulum ii; moving the magnet bar M to and fro through thecoil generates a flow of electric current through the coil and its closecircuit, and the energy thus dissipated is, of course, fdrawn from "thekinetic energy of the pendulum. Consequently, when a small properlytimed force is applied to the pendulum tosustain its-oscillation, theamplitude of its oscillation is less when the circuit containingrthecoil 59 is closed than when the coil is open-circuited.

With the magnetic" pendulum it and the damping coil 59 in series withthe active lamp are combined means for utilizing the large amplitudeoscillation of the pendulum, which occurs when the damping coil 50 isopen-circuited by the burning out of the filament in the lamp for thepurpose of removing the burned out lamp and replacing it with a new onewhose filament is intact.

Such means include,in the form shown, a rigid double bar 6!! dependingfrom the cross-piece 52 ofthe pendulum, and carrying a projecting pin'55, and ale'ver 62 pivoted on a pin 63 extending between the mainbracket and a vertical plate fi fixed on posts 65 secured to the mainbracket. The lever 62 has at its free end a hanging trip bar 66 providedwith a shoulder 6? which is at a lower level than the pin 61 when thebar hangs vertically. A rod 58 limits downward turning of the lever 62.The trip bar E6 hangs close to the pin 6! projecting from the dependingbar 68, as shown in Fig. 1, and the shoulder Bl is so positioned.that'with only a normal amplitude oscillation of the pendulum, such asoccurs when the coil5fl is in closed circuit, the pin 6! does not moveunder the shoulder 61 but merely strikes the side of the trip bar 66 asshown in Fig. 3.

' When, however, the filament of the lamp burns out, open-circuiting thecoil 51], and the amplitude of the oscillation of the pendulum becomesgreater, the pin 6! in its left-hand swing moves far enough to enterunder the shoulder El as shown in Fig. 4, so that as the pendulum andpin start back towards the right, the pin raises the shoulder 6'5,thereby lifting the trip bar 66, and tipping up the free end of thelever 62 as shown in Fig. 5.

" The tipping up of the lever 62 may be used in various difierent waysto actuate the lamp carrier 29 so as to move the burnt out lamp awayfrom the terminal 22, and to bring the next lamp into contact with it.In the form shown in Fig. l,'the lever 62 is connected by the rod with aleveri 59 pivoted on the shaft 2d and having a downwardly extending arm69' abutting a pin til" projecting from the post 25. The

. lever $9 carries a pawl lilwhich engages a ratchet wheel lljiixed onthe lainpcarrier 2d. The movements'of the leverjfiz, which occur on thelarge 1 amplitude swings-of the pendulum'after the fila- 6? and themovement of the carrier 26 stops.

The carrier then remains stationary until the filament of the activelamp is burnt out or broken.-

A part of the abovedescribed means for damping the oscillation of thependulum may be utilized-as a means for sustaining the oscillation ofthe pendulum 3Q. This is accomplished by caus-.

ing a momentary flow of electric current through the coil 59 on eachoscillation of the pendulum in such a direction that the action of thecoil as a solenoid tends to accelerate the movement which the pendulumhas at the time. A source of electromotive force, such as the: battery89 shown diagrammatically in Fig. '10, has one of its terminalsconnected by a wire 8! to the binding post 53 and thus'to the end 5! ofthe coil 5%. The other terminal of the battery is grounded to the mainbracket i5 through a wire 82, binding post 83, wire 86 and switch 35, sothat when the switch is closed this terminal of the battery is connectedthrough ground to the end 52 of the coil 55. The switch 85 has a fixedinsulated con tact 86, and a movable contact 8'! formed by a leafspringfixed at its outer end" in a block il mounted on the plate 54 and thusgrounded to the main bracket. The binding post 33 is mounted ontheinsulating bar 5 5.

The switch 85 is closed at a predetermined point of eachoscillation ofthe pendulum'through the engagement ofthe spring contact 8? by aquadrant-shaped member 90 carried on the lower end of the 'double bar6!) of the pendulum. The quadrant-shaped engaging member at is pivotally mounted to turn freely on an axis 9i extending across the lowerend' of the doublebar 6E and is normally held in the position shown inFiglby a light coiled spring ElZ. each swing of the pendulum toward theleft in Fig. l, the concentrically curved edge 93. of the member engagesthe upwardly turned end of the leaf spring 8? and then, as the movementof the pendulum continues, the member 95 turns on its pivot withoutchanging its point of contact with the end of the spring and depressesthe spring into contact with the fixed contact member 86, as shown inFig. 9. There is thus no rubbing frictionbetweenthe pendulum and themovable contact member -of the switch, and the retardation of thependulum which would result from such rubbing contact is avoided. Theenergy expended by the pendulum in depressing the spring through therolling contact of the member 9!] with the end ofthe spring is, at leastlargely, returned to the'pendulum by the pressure of the end of thespring against the member 953 after the axis of the member 9!] haspassed beyond the line extending from the end of the spring at rightangles tothe direction of movement of said axis.

\Whell' the continued movement of the pendulum spring without depressingit, and, because of the very light force exerted by the coil spring 9!,this engagement of the member 59 with the end of the contact springoifers very little resistance to the movement of the pendulum.

The source of electromotive force and the switch are used to causeflashing of the lamp which is in operating position. This isaccomplished by means of the connections already described, since whenthe switch is closed, one terminal of the battery is connected with theterminals 29 of the lamp sockets through wires 82 and 84, the switch themain bracket and t re metallic portion of the lamp carrier which formsthe grounded lamp terminal 23, while the other terminal of the batteryis permanently connected with the lamp terminal 22 through the wire L-land conductor 55. Therefore, when the switch 85 is closed, current fromthe battery flows through both the coil 55 and the lamp filament inparallel. The coil is of relatively high resistance compared. to thelamp, so that only a small part of the current flows through the coil.

The battery or other source of electromotive force may be of highervoltage than that for which the filament of the lamp is intended and theapplication of this voltage to the lamp be cut ofi so quickly that thefilament is not heated beyond its normal operative temperature. The useof the higher voltage reduces the time required to heat the lampfilament to the desired brilliancy, and the total period of time duringwhich the current flows through the lamp is extremely short. I haveascertained that by this expedient the normal length of life of both thelamp and the battery may be increased, while at the same time theflashes although very brief may be of strong intensity so as to serve asan eifective signal. A very high efficiency is thus secured, a d siredsignal light being secured at a very low lamp and battery cost.Regulation of the length of time during which the switch 85 is closed oneach oscillation of the pendulum is accomplished in the constructionshown by adjustment of the position or" the fixed contact 85 of theswitch. To provide for such adjustment, the contact 85 is made in theform of a screw set in threaded openings in two tabs extending from aninsulated plate 9.5. in order that the contact screw shall be held inits position of adjustment, the tabs 9% after their openings are tappedare slightly relatively upset before the contact screw is inserted.

If the voltage of the battery drops due to use, the pendulum will swingat a smaller amplitude and lower speed and the switch member 8? will beheld closed for a longer period, thus compensating for the lower voltageapplied to the lamp and preventing the drop in brilliancy oi flash whichwould otherwise result from the drop in voltage of the battery.

It will be seen that the invention provides an electric circuit controlwhich is particularly suited to use with battery-operated flash beaconsand especially those employing a dampened pendulum action. On the otherhand, it will be obvious that the controlling device may be of generalapplication serving to make and interrupt a circuit with slight demandon the power source and in a manner which regulates itself favorably tothe de-. crease in energy at said source.

What is claimed is:

1. A circuit controlling device, comprising a normally open switchhaving a movable member, an oscillating member, and an engaging memberpivotally mounted on the oscillating member and shaped and normallypositioned to engage the movable switch member and to turn while inengagemcnt therewith to maintain a fixed point of engagement with theswitch member and to move the switch to close the switch on the movementof the oscillating member in one direction and on engagement with theswitch member on the movement or" the oscillating member in the otherdirection to turn and pass over the switch men: or without moving it toclose the switch.

2. A circuit controlling device, comprising a normally open switchhaving a movable member, an oscillating member, a quadrant-shapedengaging member pivotally mounted on the oscillating member, and a lightcoiled spring tending to hold the engaging member in position such thatits concentric surface comes into engagement with the movable switchmember on the movement of the oscillating member in one direction andone a of its radial surfaces comes into engagement with the movableswitch member on the movement of the oscillating member in the otherdirection, the en aging member being free to turn in either directionagainst the light resistance of its spring from its normal position inwhich the spring tends to hold it.

3. In a circuit controlling device, the combination with an oscillatingmember and a movable switch member to be operated thereby, of anengaging element pivotally mounted on one of said members, and a springnormally positioning said engaging element to engage the other memberwhen the oscillating member is swinging in one direction, the engagingparts being shaped and relatively positioned to cause pivotal movementof the engaging element and bodily movement of the movable member whilemaintaining a fixed point of engagement between them during con tinnedswing of the oscillating member in said direction, and said engagingelement being freely pivotally movable to turn and pass said othermember without moving it when the oscillating member swings in theopposite direction.

4.. In a circuit controlling device, the combine. tion with a movingmember and a movable switch member, of an engaging element pivotallymounted on one of said members and shaped and yieldingly held on itspivot normally in position to engage the other member and being free toturn in engagement with said other member to maintain a fixed point ofengagem nt therewith, thereby to move the movable member duringcontinued movement of the moving member.

CHARLES F. WALLACE.

